Reading and Clearing Diagnostic Trouble Codes

ON-BOARD DIAGNOSTICS
The Automatic air conditioning is equipped with an on-board diagnostic feature which allows the Heater and A/C Control Assembly to detect certain system faults. The diagnostic feature can also be used to display certain data parameters. If the Heater and A/C Control Assembly detects a fault in the system, the C° or F° annunciator will flash during the first two minutes of vehicle operation.

Entry into the diagnostic mode is gained by depressing the "OUTS TEMP" and BI-LEV buttons at the same time. Once the diagnostic mode is entered, any trouble codes stored will be displayed. If none are present, 00 will be displayed.

If the WARM button is depressed after the trouble codes have been displayed, the data mode will be entered. The information available in the data mode is displayed in units used by the computer which may not be of use in observing the system. To exit the diagnostic mode, press any mode button.

A list of the Trouble Codes and their meanings are shown in the figures below.

Trouble Codes Descriptions:

NOTE A two digit trouble code indicates the fault is present now. A three digit trouble code indicates an intermittent fault.

Clearing Codes
To clear codes from the Heater and A/C Control Assembly, remove ELEC Fuse.